Trainman&#39;s safety circuit



Aug. 18, 1925. 1,549,984 I L. P. HYNES TRAINMANS SAFETY CIRCUIT Filed Nov. 1924 wvw ' INVENTOR LEE P. HYNES ATTORNEY Patented Aug. 18, 1925.

UNITED STATES PATENT OFFICE.

LEE P. I-IYNES, OF ALBANY, NEW YORK, ASSIGNOR TO CONSOLIDATED CAR-HEATING COMPANY, OF ALBANY, NEW YORK, A CORPORATION OF WEST VIRGINIA.

TRAINMANS SAFETY CIRCUIT.

Application filed November 25, 1924. Serial No. 752,142.

To all whom it may concern:

Be it known that I, Lnn P. HYNES, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented certain new and useful Improvements in Trainmens Safety Circuits, the following being a full, clear, and exact disclosure of the one form of my invention which I at present deem preferable.

For a detailed description of the present form of my invention, reference may be had to the following specification and to the accompanying drawing, forming a part thereof, wherein Fig. 1 is a circuit diagram, and

Fig. 2 shows the fuse box.

My invention relates to a circuit arrangement designed particularly for the protection of trainmen in changing fuses on an electric car-heating system. It can, however,

- be used under similar conditions where fuses have to be changed or replaced, or other manipulations performed on a dangerous high-tension circuit.

It has heretofore been the practice under such conditions to provide a single so-called safety switch, of an elaborate and costly type, that will control a number of heater circuits and contains a single fuse for the entire group. By this means the one fuse could be safely changed. But a recent underwriters rule now requires an individual fuse for each separate heater circuit, which rule can only be met with existing apparatus, by providing a safety switch of the kind mentioned for each individual heater circuit, thus materially augmenting the cost of heater installations. My present invention is designed to not only meet this new requirement of the underwriters but also to eliminate the safety switch entirely. The previous function of that switch is, by my present invention, performed by the switch or circuit-breaker of the automatic regulator that maintains constant the temperature of the car or apartment to be heated.

Referring to the drawing, A is the trolley, P the main switch connecting with the trolley. and S is the main fuse. G is the regulator switch that is closed by a magnet D. From C the main heating current goes to four heater-circuits in multiple, each having its individual fuse as required by the new rule aforesaid. These fuses are marked F F F and F respectively, and each l'ieater-circuit is indicated as containing four heaters H, H, etc., in series. From the heaters the current goes to ground.

The regulator-magnet D is contained in a shunt circuit of high resistance which starts from the main circuit on the trolley side at the point a. Thence it goes through an artificial resistance, of, for example, 5000 ohms, and then to a small spring switch TV in the fuse box containing the four several fuses aforesaid F F etc. This switch W is closed by closing down the lid of the fuse box, but opens automatically on a very slight lifting of said lid. From switch TV the said shunt circuit goes through a small fuse F to the magnet D, which, when energized, holds witch C closed and thence to ground at G T is a thermostat responding to the car temperature which, at a predetermined degree, will close a circuit from fuse F to ground at G That will short-circuit magnet D, causing it to drop its armature and open the main heater circuit at C. \Vhen the car temperature drops again the thermostat T will again open the short circuit around magnet D, allowing it to again close the heater circuit at C. A manual switch V is provided which, when closed, will also short-circuit magnet D to ground at G. Instead of using the heavy main switch P to cut off the heaters as heretofore, the motorman, trainman or conductor can close this small switch V, which carries only the minute current through the high-resistance shunt circuit, and thereby cause the automatic regulator to break the main heater circuit at G just as it is frequently doing in its normal work of holding the car temperature constant as above described.

It will be observed that the shunt circuit which includes the aforesaid regulatormagnet D is also controlled by the fuse-box switch W, which is in series with magnet D in the said shunt circuit and acts to break that circuit when opened by opening the fuse box. If, therefore, a trainman desires to replace one of the fuses F F etc, in the box K, and starts to open the box for that purpose, the lifting of the box lid will at the very start open switch W thereby breaking the circuit of magnet D and opening at C the main circuit to all of the heaters. Since the heaters are then dead it is safe to replace the fuse or do whatever may be necessary with the heater circuits which would otherwise carry a voltage dangerous to life. The switch lV carries only the minute cur rent of the high-resistance shunt circuit and need be but a small one readily incorporated in the fuse box. By the above described organization it is no longer necessary to provide the safety switch. heretofore mentioned for each of the four heater circuits, nor to make use of that switch at all. lily system contains no switch in the heater circuit except the regulator switch 0, and, of course, the fundamental. switch. P which would be required in any case for use when the car goes out of service, or in some rare emergency.

lVhat 1 claim as new and desire to secure by Letters Patent is:

l. A safety electric system comprising a circuit-breaker in a heater circuit, a shunt circuit containing a magnet controlling the circuit-lneaker, a box containing a fuse in the heater circuit, and a switch in the said shunt circuit responding to the opening of said box to cause the opening of the circuit.- breaker.

2. A safety electric system comprising a circuit-breaker in a main heater circuit, branch heater circuits containing individual fuses, a box inclosing the several fuse" and means responding to the opening of said box for causing the opening of the circuit breaker.

3. A safety electric system comprising a circuit-breaker in a circuit, branch circuits containing translating devices, individual fuses for each of said branch circuits, a box enclosing said fuses and means responding to the opening of said box for causing the opening of the circuit-breaker.

l. A safety electric system comprising a circuit and a translating device therein, a fuse in said circuit and an enclosing box therefor, a circuit-breaker, a shunt circuit containing a magnet that controls said circuitbreaker and a switch controlling said shunt circuit and responsive to the opening of the fuse box.

5. A safety electric system comprising a circuit and a circuit-breaker therein, a translating device and a circuit-opener in said circuit a box containing the circuit-opener, a shunt-circuit containing the operating magnet of said circuit-breaker, and a switch controlling said shunt-circuit and responsive to the opening of said box to cause the circuit-breaker to open.

6. In a safety electric system, a circuit, a circuit-breaker and fuse therein, a shuntcircu it branching therefrom, a box containing said fuse and provided with a movable cover, a magnet in said shunt-circuit and also a switch therein operated by the move- .a thermostat controlling ment of the box-cover and controlling the magnet.

7. In a safety electric system, a circuit containing an electric heater and a fuse, a switch therein controlled by an electromagnet, a thermostat controlling the electroniagnet, a box containing said fuse and pro vided with a movable cover, and a switch in a shimt-circuit also controlling the electromagnet and operated by the movement of the box cover.

8. In a afety electric system, a main heater circuit, circuits branching therefrom, each containing one or more heaters and an individual fuse, a regulator magnet and thermostat for maintaining the temperature of the heated apartment within prescribed limits, a box containing the fuses for the several branch circuits, a switch controlling said regulator magnet and arranged to be operated automatically by the opening of the fuse box, and a manual switch also controlling the said magnet.

9. A safety circuit for electric heaters comprising a main circuit with a circuit breaker therein operated by a shunt magnet, said magnet, two or more branch circuits each containing two or more heaters and an individual fuse, a box for said fuses, and a switch responding to the opening of the fuse box for controlling the said magnet.

10. A safety circuit for electric heaters comprising a main circuit and circuitbrealtcr therein, a plurality of branch cir cuits each containing heater and a fuse, a box containing the several fuses, a shunt magnet acting when energized to hold said circuit-breaker closed, a theru'iostat acting at its upper prescribed limit to short-circuit said magnet and thereby open the circuitbreaker, a manual switch also acting to short-circuit the said magnet, and a switch responding to the opening of the fuse box for opening the magnet circuit.

11. A safety circuit for electric heaters comprising a main circuit and a circuitbreaker therein, branch circuits each containing an electric heater and a fuse in series therewith, a regulator magnet acting when energized to hold said circuit-breaker closed, a high-resistance shunt circuit including said magnet and a low-current fuse, a thermostat acting at its upper limit to short-circuit said magnet, a manual switch for also short-circuiting the magnet, and a switch for opening the magnet circuit rcsponsive to the opening of a box containing the several heater fuses.

Signed at Albany, county of Albany and State of New York, this 22 day of November, 1924..

LEE P. HYNES. 

